<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <style type="text/css">
    body{
    	width: 100%;
    	margin: 0;
    	background: grey;
    }
    .container{
    	width: 75%;
    	margin: 75px 10% 0;
    	background: white;
    	box-shadow: 10px 10px 15px black;
      text-align:center;
    }
    a{
      display:inline-block;
      font-size: 30px;
    }
</style>
  <title>首页</title>
</head>
<body>
<div class="container">
  <a href="https://cas.dgut.edu.cn?appid=javaee&secret=b3b52e43ccfd" >登录</a>
</div>
</body>
</html>
